Technical Field
The present subject matter relates to an onboard unit for a traffic telematics system. The present subject matter further relates to an onboard system for a vehicle comprising such an onboard unit.
Background Art
Onboard units (OBUs) are used in a large number of different applications of traffic telematics systems, whether for electronic identification of a vehicle or for payment of road, access, area or city tolls, for payment of parking fees, for access control (for example barrier systems), for electronic vehicle registration (EVR), etc. For this purpose, onboard units are often equipped with a short-range communication module, for example in accordance with the DSRC (dedicated short range communication) standard, so that they can be localised to the local radio coverage range of an interrogating radio beacon. Here, the communication module is supplied with power together with the rest of the electronics of the onboard unit by a battery installed in the onboard unit.
In order to save power and to achieve a long service life of the battery, onboard units or the communication module thereof generally have a power-supplied or power-consuming working and communication mode and a power-saving rest mode. By addressing the onboard unit by means of an external communication device, for example a radio beacon of a road toll system, an access barrier, a control device or the like, the onboard unit can be awakened from its rest mode and shifted temporarily into its working or communication mode; it then lapses back into the rest mode until the next communication. Commercially obtainable onboard units can currently achieve a battery service life of up to seven years in this way.